Efficiently Measuring Bandwidth at All Time Scales
The need to identify correlated traffic bursts at various, and especially fine-grain, time scales has become pressing in modern data centers. The combination of Gigabit link speeds and small switch buffers have led to "Microbursts", which cause packet drops and large increases in latency. The paper describes the design and implementation of an efficient and flexible end-host bandwidth measurement tool that can identify such bursts in addition to providing a number of other features. Managers can query the tool for bandwidth measurements at resolutions chosen after the traffic was measured. The algorithmic challenge is to support such a posteriori queries without retaining the entire trace or keeping state for all time scales.